/* ============================================
   Main Stylesheet - Yasodh Jayathilake Portfolio
   ============================================ */

/* CSS Variables for easy theming */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --nav-height: 70px;
    --container-width: 1200px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;
    --transition-speed: 0.3s;
}

/* ============================================
   Reset and Base Styles
   ============================================ */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
                 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
                 sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   Typography
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: var(--spacing-sm);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-speed);
}

a:hover {
    color: var(--primary-hover);
}

/* ============================================
   Layout Components
   ============================================ */

.container {
    max-width: 100%;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.main-content {
    min-height: calc(100vh - var(--nav-height) - 100px);
    padding-top: var(--nav-height);
}

/* ============================================
   Navigation
   ============================================ */

.main-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background-color: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.nav-container {
    max-width: 100%;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    height: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand a {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-color);
    transition: color var(--transition-speed);
}

.nav-brand a:hover {
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-md);
}

.nav-link {
    color: var(--text-color);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: 4px;
    transition: all var(--transition-speed);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
    background-color: var(--bg-secondary);
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    font-weight: 500;
    text-align: center;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: all var(--transition-speed);
    text-decoration: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

/* ============================================
   Home Page Sections
   ============================================ */

.hero {
    padding: var(--spacing-xl) 0;
    text-align: center;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-color) 100%);
}

.hero h1 {
    margin-bottom: var(--spacing-sm);
    color: var(--text-color);
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.intro {
    padding: var(--spacing-xl) 0;
}

.intro h2 {
    margin-bottom: var(--spacing-md);
}

/* ============================================
   Contact Page
   ============================================ */

.contact-section {
    padding: var(--spacing-xl) 0;
}

.contact-section h1 {
    margin-bottom: var(--spacing-sm);
}

.contact-section p {
    color: var(--text-light);
    margin-bottom: var(--spacing-lg);
}

.contact-form-container {
    margin-top: var(--spacing-lg);
    border-radius: 16px;
    padding: var(--spacing-xl);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    background: #f5f5f0;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-md);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-weight: 500;
    color: #4a4a4a;
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.form-group .required {
    color: #dc2626;
}

.form-group input,
.form-group textarea,
.form-group select {
    padding: 1rem 1.25rem;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-family: inherit;
    transition: all var(--transition-speed);
    background: var(--bg-color);
    color: var(--text-color);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.form-group select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%234a4a4a' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1.25rem center;
    cursor: pointer;
}

.form-group textarea {
    border-radius: 24px;
    resize: vertical;
    min-height: 150px;
    padding: 1.25rem 1.5rem;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15), 0 2px 8px rgba(0, 0, 0, 0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: #999;
}

.form-group input:invalid:not(:placeholder-shown),
.form-group textarea:invalid:not(:placeholder-shown) {
    border: 2px solid #fca5a5;
}

.form-group input:valid:not(:placeholder-shown),
.form-group textarea:valid:not(:placeholder-shown) {
    border: 2px solid #6ee7b7;
}

.submit-btn {
    margin-top: var(--spacing-sm);
    position: relative;
    min-width: 150px;
}

.submit-btn .btn-loading {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.form-message {
    padding: var(--spacing-sm);
    border-radius: 6px;
    font-size: 0.95rem;
    text-align: center;
}

.form-message.success {
    background-color: #d1fae5;
    color: #065f46;
    border: 1px solid #6ee7b7;
}

.form-message.error {
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

/* Responsive adjustments for contact form */
@media (max-width: 768px) {
    .contact-form-container {
        padding: var(--spacing-md);
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    .contact-form-container {
        padding: var(--spacing-sm);
    }

    .form-group input,
    .form-group textarea,
    .form-group select {
        font-size: 16px; /* Prevents zoom on iOS */
        padding: 0.875rem 1rem;
    }

    .form-group textarea {
        padding: 1rem 1.25rem;
    }
}

/* ============================================
   Footer
   ============================================ */

.main-footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-md) 0;
    text-align: center;
    margin-top: var(--spacing-xl);
}

.main-footer p {
    color: var(--text-light);
    margin-bottom: 0;
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 768px) {
    :root {
        --nav-height: 60px;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .nav-menu {
        gap: var(--spacing-sm);
    }

    .nav-link {
        padding: var(--spacing-xs);
        font-size: 0.9rem;
    }

    .hero h1 {
        font-size: 1.75rem;
    }

    .hero p {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }

    .nav-container {
        padding: 0 var(--spacing-sm);
    }

    .nav-brand a {
        font-size: 1rem;
    }

    .nav-menu {
        gap: var(--spacing-xs);
    }
}

/* ============================================
   Utility Classes
   ============================================ */

.loading {
    text-align: center;
    padding: var(--spacing-lg);
    color: var(--text-light);
    font-style: italic;
}

.error {
    padding: var(--spacing-md);
    background-color: #fee;
    border: 1px solid #fcc;
    border-radius: 6px;
    color: #c33;
}

.hidden {
    display: none !important;
}